HackSpace – September 2019

(Jacob Rumans) #1
FORGE

only really need to sharpen the angled side of the
blade, unless there are any burrs that stick up from
the flat side of the blade. For planes and chisels, in
particular, you might find it easier to sharpen the
blades if you use a wedge to help you keep the
correct angle between the stone and the blade.
The trickiest types of tool to sharpen with
whetstones are scythes, sickles, and bill-hooks.
Unlike knives that might have a convex curve near
the end of the blade, these tools have a concave
curve that makes it hard to get good contact
between a normal whetstone and the edge of the


blade. For this type of tool, you can buy conical
barrel-shaped whetstones that will better match the
curve of the blade.
The technique for these shaped stones is the
reverse of a normal whetstone. You hold the blade
stationary while working the stone along the length
of the blade.


AVOID THE DAILY GRIND
If you want to sharpen your tools more quickly, you
might consider using a bench grinder, wet and dry
grinder, or a linisher (a belt sander) instead of a
whetstone. Aside from the obvious ferocity of
grinders and linishers, you need to take a lot of care
when using them to sharpen a blade. You should
carefully consider the type of grinding wheel you use.
Grinders and linishers move an abrasive belt or
disc at very high speed, and that will remove a lot of


material from your blade in a very short time. Finer
belts or discs are much better for sharpening tools on
a grinder. The high speed of the grinder also results in
more friction, and that heats up the part that you’re
working on. If your blade gets too hot during grinding,
it can ruin the tempering and hardening of a blade.
To help stop this from happening, you can apply some
light oil to the blade before you start grinding. Move
the blade evenly across the abrasive surface applying
a minimal amount of pressure, and keeping a fixed
angle between the edge of the blade and the wheel
or belt. Remember that even a small bench grinder
has enough power to pull a blade from your hands
and fire it at high speed across the room. Safety is
very important with these types of machine.

YOU’LL NEED
Whetstone
Scythe-stone
Mill file
Three-point file
Angle guide
or protractor

Above
The right amount of
oiS and SiNht finNer
pressure will help
keep the blade
moving smoothly
without dripping all
over the table
Left
Finding a comfortable
position to sharpen
a curved blade is
half of the battle. You
should always have a
firT Nrip on the tooS
handle and the stone

A 400/1000 grit
double-sided
whetstone is a good
choice in a general
workshop.

QUICK TIP


You should carefully
consider the type of
grinding wheel you use


Free download pdf